One system known in the art is configured of an image-processing device, a push notification server, and a portable terminal. The image-processing device generates event messages and transmits the event messages to the push notification server. The push notification server receives the event messages from the image-processing device and transmits the event messages to the portable terminal as push notifications. The portable terminal displays the event messages received in the push notifications. The event messages may also include status information indicating the status of the image-processing device, for example.